Ventilator-initiated prompt regarding detection of fluctuations in resistance

ABSTRACT

This disclosure describes systems and methods for monitoring ventilatory parameters, analyzing ventilatory data associated with those parameters, and providing useful notifications and/or recommendations to clinicians. For example, many clinicians may not easily identify or recognize data patterns and correlations indicative of a fluctuation in resistance during mechanical ventilation of a patient. Furthermore, clinicians may not easily determine potential causes for the fluctuation in resistance and/or steps for mitigating the fluctuation in resistance. According to embodiments, a ventilator may be configured to monitor and evaluate diverse ventilatory parameters to detect fluctuations in resistance and may issue suitable notifications and recommendations to the clinician based on potential causes of the fluctuation, ventilatory and/or patient data, etc. The suitable notifications and recommendations may further be provided in a hierarchical format such that the clinician may selectively access information regarding the fluctuation in resistance.

INTRODUCTION

A ventilator is a device that mechanically helps patients breathe byreplacing some or all of the muscular effort required to inflate anddeflate the lungs. In recent years, there has been an accelerated trendtowards an integrated clinical environment. That is, medical devices arebecoming increasingly integrated with communication, computing, andcontrol technologies. As a result, modern ventilatory equipment hasbecome increasingly complex, providing for detection, monitoring, andevaluation of a myriad of ventilatory parameters during ventilation of apatient. However, due to the shear magnitude of available ventilatorydata, many clinicians may not readily assess and evaluate the availabledata to detect certain patient conditions and/or changes in patientcondition.

Specifically, fluctuations in resistance may be indicative of a numberof disparate patient and/or ventilator conditions. The location of achange in resistance may be an important factor in determining the causefor the change. However, this may be difficult for a clinician todetermine as resistance may arise in the patient airway, the artificialairway (endotracheal or tracheostomy tube), the inspiratory limb or theexpiratory limb of the ventilatory circuit, the expiratory filter, etc.For example, an increase in resistance may be detrimental to patientcondition due to an increase in the work of breathing (WOB) and may leadto other adverse consequences such as Auto-PEEP. Furthermore, anincrease in resistance may be the result of a variety of diverse causesincluding, inter alia, mucous buildup in the artificial airway, a kinkor obstruction in the ventilatory circuit, an obstructed expiratoryfilter, changing lung conditions, poor patient position, etc. Incontrast, a decrease in resistance may be indicative of changing lungconditions, a leak in the ventilatory circuit, improved patientposition, etc. Fluctuations in resistance are difficult to detectbecause resistance is generally not measured directly, but may beimplicated by slight changes in a variety of different parameters.Furthermore, due to the variety of potential causes, fluctuations inresistance may be difficult for a clinician to efficiently andeffectively address during the ventilation of a patient.

Ventilator-Initiated Prompt Regarding Detection of Fluctuations inResistance

This disclosure describes systems and methods for monitoring andevaluating ventilatory parameters, analyzing ventilatory data associatedwith those parameters, and providing useful notifications and/orrecommendations to clinicians. Modern ventilators monitor, evaluate, andgraphically represent a myriad of ventilatory parameters. However, manyclinicians may not easily identify or recognize data patterns andcorrelations indicative of certain patient conditions, changes inpatient condition, and/or effectiveness of ventilatory treatment.Further, clinicians may no readily determine appropriate ventilatoryadjustments that may address certain patient conditions and/or theeffectiveness of ventilatory treatment. Specifically, clinicians may notreadily detect or recognize fluctuations in resistance during mechanicalventilation of a patient. According to embodiments, a ventilator may beconfigured to monitor and evaluate diverse ventilatory parameters todetect fluctuations in resistance and may issue suitable notificationsand recommendations to the clinician depending on potential causes ofthe fluctuation, the magnitude of the fluctuation, ventilatory and/orpatient data, etc. The suitable notifications and recommendations mayfurther be provided in a hierarchical format such that the clinician mayselectively access summarized and/or detailed information regarding thefluctuation in resistance. In more automated systems, recommendationsmay be automatically implemented to mitigate the detected fluctuation inresistance.

According to embodiments, a ventilator-implemented method is providedfor issuing a prompt in response to detecting a fluctuation inresistance during ventilation of a patient. The method comprisesretrieving ventilatory data and identifying a maximum threshold and aminimum threshold for resistance. Further, the method comprises trendingresistance during ventilation of the patient and detecting a fluctuationin resistance when the trended resistance breaches one of the maximumthreshold and the minimum threshold. Upon detection of the fluctuationin resistance, the method includes displaying a notification.

According to additional embodiments, a ventilatory system for issuing aprompt in response to detecting a fluctuation in resistance duringventilation of a patient is provided. The ventilatory system performs amethod that comprises retrieving ventilatory data and identifying amaximum threshold and a minimum threshold for resistance. Further, themethod comprises trending resistance during ventilation of the patientand detecting a fluctuation in resistance when the trended resistancebreaches one of the maximum threshold and the minimum threshold. Upondetection of the fluctuation in resistance, the method includesdisplaying a notification.

According to additional embodiments, a ventilator processing interfacefor displaying one or more prompts in response to detecting afluctuation in resistance is provided. The ventilator processinginterface comprises a means for retrieving at least some ventilatorydata, a means for determining the fluctuation in resistance, and meansfor displaying a prompt comprising a notification of the fluctuation inresistance.

According to additional embodiments, a graphical user interface fordisplaying one or more prompts in response to detecting a fluctuation inresistance is provided. The graphical user interface comprising at leastone window, the at least one window having one or more elementscomprising at least one prompt element for communicating informationregarding detection of a fluctuation in resistance. For example, the atleast one prompt element displays a notification regarding thefluctuation in resistance.

These and various other features as well as advantages whichcharacterize the systems and methods described herein will be apparentfrom a reading of the following detailed description and a review of theassociate drawings. Additional features are set forth in the descriptionwhich follows, and in part will be apparent from the description, or maybe learned by practice of the technology. The benefits and features ofthe technology will be realized and attained by the structureparticularly pointed out in the written description and claims hereof aswell as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawing figures, which form a part of this application,are illustrative of described technology and are not meant to limit thescope of the claims in any manner, which scope shall be based on theclaims appended hereto.

FIG. 1 is a diagram illustrating an embodiment of an exemplaryventilator connected to a human patient.

FIG. 2 is a block-diagram illustrating an embodiment of a ventilatorysystem for monitoring and evaluating ventilatory parameters associatedwith fluctuations in resistance.

FIG. 3 is a flow chart illustrating an embodiment of a method forissuing a prompt upon detecting an increase or a decrease in resistance.

FIG. 4 is a flow chart illustrating an embodiment of a method forissuing a prompt upon determining one or more potential causes for anincrease or a decrease in resistance.

FIG. 5 is a flow chart illustrating an embodiment of a method of issuinga prompt upon determining one or more recommendations for mitigating anincrease or a decrease in resistance.

FIG. 6 is an illustration of an embodiment of a graphical user interfacedisplaying a prompt comprising an increased resistance notification anda recommendation for mitigating the increased resistance.

FIG. 7 is an illustration of an embodiment of a graphical user interfacedisplaying a prompt comprising an increased resistance notification andan expanded prompt comprising one or more recommendations for mitigatingthe increase in resistance during ventilation of a patient.

FIG. 8 is an illustration of an embodiment of a graphical user interfacedisplaying a prompt comprising an increased resistance notification anda potential cause notification and an expanded prompt comprising one ormore recommendations for mitigating the increased resistance duringventilation of a patient.

DETAILED DESCRIPTION

Although the techniques introduced above and discussed in detail belowmay be implemented for a variety of medical devices, the presentdisclosure will discuss the implementation of these techniques for usein a mechanical ventilator system. The reader will understand that thetechnology described in the context of a ventilator system could beadapted for use with other therapeutic equipment for altering andadvising clinicians regarding change in patient condition.

According to embodiments, the ventilator may be configured to collectventilatory data by monitoring and evaluating diverse ventilatoryparameters and/or patient physiological data. Based on the ventilatorydata, the ventilator may issue suitable notifications andrecommendations to the clinician upon detecting a fluctuation inresistance. That is, the ventilator may detect an increase or a decreasein resistance based on, inter alia, ventilatory data (e.g., flow,volume, pressure, compliance, ventilator setup data, etc.), patient data(e.g., a patient body weight, a patient diagnosis, a patient gender, apatient age, etc.) and/or any suitable protocol, equation, etc. Theventilator may also detect an increase or a decrease in resistance at aparticular location with the ventilatory system, e.g., expiratory limb,patient airway, etc. Furthermore, the ventilator may detect one or moreprojected causes of the increase or the decrease in resistance (e.g.,clogged expiratory filter, leak in the ventilatory circuit, condensateaccumulation in the ventilatory circuit, mucous plugging of the patientairway, etc.) based on whether an increase or decrease in resistance wasdetected, a location of the increase or decrease, patient data, etc.Based on the one or more projected causes of the fluctuation, theventilator may be configured to provide a notification and/or one ormore recommendations for mitigating the detected fluctuation inresistance.

These and other embodiments will be discussed in further detail withreference to the following figures.

Ventilator System

FIG. 1 is a diagram illustrating an embodiment of an exemplaryventilator connected to a human patient.

FIG. 1 illustrates ventilator 100 connected to a human patient 150.Ventilator 100 includes a pneumatic system 102 (also referred to as apressure generating system 102) for circulating breathing gases to andfrom patient 150 via the ventilation tubing system 130, which couplesthe patient to the pneumatic system via an invasive (e.g., endotrachealtube, as shown) or a non-invasive (e.g., nasal mask) patient interface.

Ventilation tubing system 130 may be a two-limb (shown) or a one-limbcircuit for carrying gases to and from the patient 150. In a two-limbembodiment, a fitting, typically referred to as a “wye-fitting” 170, maybe provided to couple a patient interface 180 (as shown, an endotrachealtube) to an inspiratory limb 132 and an expiratory limb 134 of theventilation tubing system 130.

Pneumatic system 102 may be configured in a variety of ways. In thepresent example, system 102 includes an expiratory module 108 coupledwith the expiratory limb 134 and an inspiratory module 104 coupled withthe inspiratory limb 132. Compressor 106 or other source(s) ofpressurized gases (e.g., air, oxygen, and/or helium) is coupled withinspiratory module 104 to provide a gas source for ventilatory supportvia inspiratory limb 132.

The pneumatic system 102 may include a variety of other components,including mixing modules, valves, sensors, tubing, accumulators,filters, etc. Controller 110 is operatively coupled with pneumaticsystem 102, signal measurement and acquisition systems, and an operatorinterface 120 that may enable an operator to interact with theventilator 100 (e.g., change ventilator settings, select operationalmodes, view monitored parameters, etc.). Controller 110 may includememory 112, one or more processors 116, storage 114, and/or othercomponents of the type commonly found in command and control computingdevices. In the depicted example, operator interfaced 120 includes adisplay 122 that may be touch-sensitive and/or voice-activated, enablingthe display to serve both as an input and output device.

The memory 112 includes non-transitory, computer-readable storage mediathat stores software that is executed by the processor 116 and whichcontrols the operation of the ventilator 100. In an embodiment, thememory 112 includes one or more solid-state storage devices such asflash memory chips. In an alternative embodiment, the memory 112 may bemass storage connected to one or more processors 116 through a massstorage controller (not shown) and a communications bus (not shown).Although the description of computer-readable media contained hereinrefers to a solid-state storage, it should be appreciated by thoseskilled in the art that computer-readable storage media can be anyavailable media that can be accessed by the one or more processors 116.That is, computer-readable storage media includes non-transitory,volatile and non-volatile, removable and non-removable media implementedin any method or technology for storage of information such ascomputer-readable instructions, data structures, program modules orother data. For example, computer-readable storage media includes RAM,ROM, EPROM, EEPROM, flash memory or other solid state memory technology,CD-ROM, DVD, or other optical storage, magnetic cassettes, magnetictape, magnetic disk storage or other magnetic storage devices, or anyother medium which can be used to store the desired information andwhich can be accessed by the computer.

Communication between components of the ventilatory system or betweenthe ventilatory system and other therapeutic equipment and/or remotemonitoring systems may be conducted over a distributed network, asdescribed further herein, via wired or wireless means. Further, thepresent methods may be configured as a presentation layer built over theTCP/IP protocol. TCP/IP stands for “Transmission ControlProtocol/Internet Protocol” and provides a basic communication languagefor many local networks (such as intra- or extranets) and is the primarycommunication language for the Internet. Specifically, TCP/IP is abi-layer protocol that allows for the transmission of data over anetwork. The higher layer, or TCP, layer, divides a message into smallerpackets, which are reassembled by a receiving TCP layer into theoriginal message. The lower layer, or IP layer, handles addressing androuting of packets so that they are properly received at a destination.

Ventilator Components

FIG. 2 is a block-diagram illustrating an embodiment of a ventilatorysystem for monitoring and evaluating ventilatory parameters associatedwith fluctuations in resistance.

Ventilatory system 200 includes ventilator 202 with its various modulesand components. That is, ventilator 202 may further include, inter alia,memory 208, one or more processors 206, user interface 210, andventilation module 212 (which may further include an inspiration module214 and an exhalation module 216). According to embodiments, theexhalation module 216 may be associated with an expiratory filter forpreventing mucous and other debris from passing into the ventilator.Memory 208 is defined as described above for memory 112. Similarly, theone or more processors 206 are defined as described above for one ormore processors 116. Processors 206 may further be configured with aclock whereby elapsed time may be monitored by the system 200.

The ventilatory system 200 may also include a display module 204communicatively coupled to ventilator 202. Display module 204 mayprovide various input screens, for receiving clinician input, andvarious display screens, for presenting useful information to theclinician. The display module 204 is configured to communicate with userinterface 210 and may include a graphical user interface (GUI). The GUImay be an interactive display, e.g., a touch-sensitive screen orotherwise, and may provide various windows and elements for receivinginput and interface command operations. Alternatively, other suitablemeans of communication with the ventilator 202 may be provided, forinstance by a wheel, keyboard, mouse, or other suitable interactivedevice. Thus, user interface 201 may accept commands and input throughdisplay module 204. Display module 204 may also provide usefulinformation in the form of various data regarding the physical conditionof a patient and/or a prescribed respiratory treatment. The usefulinformation may be based on data collected by monitor module 218 or dataderived or otherwise processed by data processing module 220, and theuseful information may be displayed to the clinician in the form ofgraphs, wave representations, pie graphs, or other suitable forms ofgraphic display. For example, one or more smart prompts may be displayedon the GUI of display module 204 upon detection of a fluctuation inresistance by the ventilator. Additionally or alternatively, one or moresmart prompts may be communicated to a remote monitoring system coupledvia any suitable means to the ventilatory system 200.

Equation of Motion

Ventilation module 212 may oversee ventilation of a patient according toprescribed ventilatory settings. By way of general overview, the basicelements impacting ventilation may be described by the followingventilatory equation (also known as the Equation of Motion):

P _(m) +P _(v) =V _(T) /C+R*F

Here, P_(m) is a measure of muscular effort that is equivalent to thepressure generated by the muscles of a patient. If the patient's musclesare inactive, the P_(m) is equivalent to 0 cm H₂O. During inspiration,P_(v) represents the positive pressure delivered by a ventilator(generally in cm H₂O). V_(T) represents the tidal volume delivered basedon the pressure supplied, C refers to the compliance, R represents theresistance, and F represents the gas flow during inspiration (generallyin liters per min (L/m)). Alternatively, during exhalation, the Equationof Motion may be represented as:

P _(a) +P _(t) =V _(TE) /C+R*F

Here, P_(a) represents the positive pressure existing in the lungs(generally in cm H₂O), P_(t) represents the transairway pressure, V_(TE)represents the tidal volume exhaled, C refers to the compliance, Rrepresents the resistance, and F represents the gas flow duringexhalation (generally in liters per min (L/m)).

Pressure

For positive pressure ventilation, pressure at the upper airway opening(e.g., in the patient's mouth) is positive relative to the pressure atthe body's surface (i.e., relative to the ambient atmospheric pressureto which the patient's body surface is exposed, about 0 cm H₂O). Assuch, when P_(v) is zero, i.e., no ventilatory pressure is beingdelivered, the upper airway opening pressure will be equal to theambient pressure (i.e., about 0 cm H₂O). However, when inspiratorypressure is applied (i.e., positive pressure), a pressure gradient iscreated that allows gases to flow into the airway and ultimately intothe lungs of a patient during inspiration (or, inhalation) until thepressure is equalized. When an inspiratory volume (or V_(T)) has beendelivered to the lungs such that the inspiratory pressure is achievedand maintained, pressure is equalized and gases no longer flow into thelungs (i.e., zero flow).

Flow and Volume

Volume refers to the amount of gas delivered to a patient's lungs,usually in liters (L). Flow refers to a rate of change in volume overtime (F=ΔV/Δt). Flow is generally expressed in liters per minute (L/m orlpm) and, depending on whether gases are flowing into or out of thelungs, flow may be referred to as inspiratory flow or expiratory flow,respectively. According to embodiments, the ventilator may control therate of delivery of gases to the patient, i.e., inspiratory flow, andmay control the rate of release of gases from the patient, i.e.,expiratory flow.

As may be appreciated, volume and flow are closely related. That is,where flow is known or regulated, volume may be derived based on elapsedtime. Indeed, volume may be derived by integrating the flow waveform.According to embodiments, a tidal volume, V_(T), may be delivered uponreaching a set inspiratory time (T_(I)) at set inspiratory flow.Alternatively, set V_(T) and set inspiratory flow may determine theamount of time required for inspiration, i.e., T_(I).

Compliance

Additional ventilatory parameters that may be measured and/or derivedmay include compliance and resistance, which refer to the load againstwhich the patient and/or the ventilator must work to deliver gases tothe lungs. Generally, compliance refers to a relative ease with whichsomething distends and is the inverse of elastance, which refers to thetendency of something to return to its original form after beingdeformed. As related to ventilation, compliance refers to the lungvolume achieved for a given amount of delivered pressure (C=ΔV/ΔP).Increased compliance may be detected when the ventilator measures anincreased volume relative to the given amount of delivered pressure.Some lung diseases (e.g., acute respiratory distress syndrome (ARDS))may decrease compliance and, thus, require increased pressure to inflatethe lungs. Alternatively, other lung diseases may increase compliance,e.g., emphysema, and may require less pressure to inflate the lungs.

Resistance

Resistance refers to frictional forces that resist airflow, e.g., due tosynthetic structures (e.g., endotracheal tube, expiratory valve, etc.),anatomical structures (e.g., bronchial tree, esophagus, etc.), orviscous tissues of the lungs and adjacent organs. Resistance is highlydependant on the diameter of the airway. That is, a larger airwaydiameter entails less resistance and a higher concomitant flow.Alternatively, a smaller airway diameter entails higher resistance and alower concomitant flow. In fact, decreasing the diameter of the airwayresults in an exponential increase in resistance (e.g., two-timesreduction of diameter increases resistance by sixteen times). As may beappreciated, resistance may also increase due to a restriction of theairway that is the result of, or inter alia, increased secretions,bronchial edema, mucous plugs, brochospasm, and/or kinking of thepatient interface (e.g., invasive endotracheal or tracheostomy tubes).

Airway resistance may further be represented mathematically as:

R=P _(t) /F

Where P_(t) refers to the transairway pressure and F refers to the flow.That is, P_(t) refers to the pressure necessary to overcome resistiveforces of the airway. Resistance may be expressed in centimeters ofwater per liter per second (i.e., cm H₂O/L/s).

Pulmonary Time Constant

As discussed above, compliance refers to the lung volume achieved for agiven amount of delivered pressure (C=ΔV/ΔP). That is, stateddifferently, volume delivered is equivalent to the compliance multipliedby the delivered pressure (ΔV=C*ΔP). However, as the lungs are notperfectly elastic, a period of time is needed to deliver the volume ΔVpressure ΔP. A pulmonary time constant τ, may represent a time necessaryto inflate or exhale a given percentage of the volume at deliveredpressure ΔP. The pulmonary time constant, τ, may be calculated bymultiplying the resistance by the compliance (τ=R*C) for a given patientand τ is generally represented in seconds, s. The pulmonary timeconstant associated with exhalation of the given percentage of volumemay be termed an expiratory time constant and the pulmonary timeconstant associated with inhalation of the given percentage of volumemay be termed an inspiratory time constant.

According to some embodiments, when expiratory resistance data isavailable, the pulmonary time constant may be calculated by multiplyingexpiratory resistance by compliance. According to alternativeembodiments, the pulmonary time constant may be calculated based oninspiratory resistance and compliance. According to further embodiments,the expiratory time, T_(E), should be equal to or greater than apredetermined number of pulmonary time constants (e.g., about threepulmonary time constants) to ensure adequate exhalation. Thepredetermined number of pulmonary time constants may be selected via anysuitable means, e.g., a standard protocol, an institutional protocol,clinician input, etc. According to embodiments, for a triggeringpatient, T_(E) (e.g., determined by trending T_(E) or otherwise) shouldbe equal to or greater than the predetermined number of pulmonary timeconstants. For a non-triggering patient, set RR should yield a T_(E)that is equal to or greater than the predetermined number of pulmonarytime constants.

Normal Resistance and Compliance

According to embodiments, normal resistance and compliance may bedetermined based on a patient's predicted body weight (PBW) (or idealbody weight (IBW)). That is, according to a standardized protocol orotherwise, patient data may be compiled such that normal resistance andcompliance values and/or ranges of values may be determined and providedto the ventilatory system. As such, a manufacturer, clinical facility,clinician, or otherwise, may configure the ventilator with normalresistance and compliance values and/or ranges of values based on PBWs(or IBWs) of a patient population. Thereafter, during ventilation of aparticular patient, resistance and compliance data may be trended forthe patient and compared to normal values and/or ranges of values basedon the particular patient's PBW (or IBW). According to embodiments, theventilator may give an indication to the clinician regarding whether thetrended resistance and compliance data of the particular patient fallsinto normal ranges. According to some embodiments, data may be morereadily available for trending resistance and compliance fornon-triggering patients than for triggering patients.

According to further embodiments, a predicted T_(E) may be determinedbased on a patient's PBW (or IBW). That is, according to a standardizedprotocol or otherwise, patient population data may be compiled such thatpredicted T_(E) values and/or ranges of values may be determined basedon PBWs (or IBWs) of the patient population and provided to theventilatory system. Actual (or trended) T_(E) for a particular patientmay then be compared to the predicted T_(E). As noted previously,increased resistance and/or compliance may result in an actual T_(E)that is longer than predicted T_(E). However, when actual T_(E) isconsistent with predicted T_(E), this may indicate that resistance andcompliance for the particular patient fall into normal ranges.

According to further embodiments, a normal pulmonary time constant, τ,may be determined based on a patient's PBW (or IBW). That is, accordingto a standardized protocol or otherwise, patient data may be compliedsuch that normal τ values and/or ranges of values may be determinedbased on PBWs (or IBWs) of a patient population and provided to theventilatory system. A calculated τ may be determined for a particularpatient by multiplying resistance by compliance (as described above,resistance and compliance data may be more readily available for anon-triggering patient). As the product of resistance and complianceresults in τ, increased resistance and/or compliance may result in anelevated τ value. However, when the calculated τ value for theparticular patient is consistent with the normal τ value, this mayindicate that the resistance and compliance of the particular patientfall into normal ranges.

Patient Data

According to embodiments, patient data may be received by the ventilator202. Patient data (including a patient diagnosis, a patient disability,a patient post-operative condition, a patient body weight, a patientgender, a patient age, etc.) may influence the ventilator'sdetermination of the one or more causes for fluctuations in resistance.Furthermore, patient data may influence the ventilator's determinationof one or more appropriate recommendations for mitigating thefluctuation in resistance. As such, according to some embodiments, theventilator may take into consideration patient data when determiningpotential causes and/or recommendations for fluctuations in resistance.

Some patients may exhibit certain characteristics associated withvarious conditions and diseases, e.g., COPD, ARDS, post-operativecondition (single lung, cardiac surgery), etc. For example, patientsdiagnosed with COPD may exhibit chronic elevated resistance due toconstricted and/or collapsed airways, while ARDS patients may exhibitchronic elevated resistance due to an inflammatory condition of theairways. In some cases, patients diagnosed with various condition anddiseases associated with an obstructive component may exhibit elevatedresistance over many months or years. According to some embodiments,patients having these conditions may also exhibit elevated compliance.

According to embodiments described herein, a clinician may input apatient diagnosis, e.g., COPD, ARDS, emphysema, etc. The ventilator mayassociated the patient diagnosis with certain lung and airwaycharacteristics. For example, if the ventilator receives a patientdiagnosis of COPD, the ventilator may associated this patient diagnosiswith elevated resistance. The ventilator may further associate thispatient diagnosis with an obstructive component. Alternatively, if theventilator receives a patient diagnosis of emphysema, the ventilator mayassociate this patient diagnosis with elevated compliance. Alternativelystill, a patient diagnosis of ARDS may be associated with increasedresistance and/or decreased lung compliance.

Inspiration

Ventilation module 212 may further include an inspiration module 214configured to deliver gases to the patient according to prescribedventilatory settings. Specifically, inspiration module 214 maycorrespond to the inspiratory module 104 or may be otherwise coupled tosource(s) of pressurized gases (e.g., air, oxygen, and/or helium), andmay deliver gases to the patient. Inspiration module 214 may beconfigured to provide ventilation according to various ventilatorymodes, e.g., via volume-targeted, pressure-targeted, or via any othersuitable mode of ventilation.

According to embodiments, the inspiration module 214 may provideventilation via a form of volume ventilation. Volume ventilation refersto various forms of volume-targeted ventilation that regulate volumedelivery to the patient. Different modes of volume ventilation areavailable depending on the specific implementation of volume regulation.For example, for volume-cycled ventilation, an end of inspiration isdetermined based on monitoring the volume delivered to the patient.According to embodiments, during volume ventilation, as volume and floware regulated by the ventilator, delivered V_(T), flow waveforms (orflow traces), and volume waveforms may be constant and may not beaffected by variations in lung or airway characteristics (e.g.,compliance and/or resistance). Alternatively, pressure readings mayfluctuate based on lung or airway characteristics. According to someembodiments, the ventilator may control the inspiratory flow and thenderive volume based on the inspiratory flow and elapsed time. Forvolume-cycled ventilation, when the derived volume is equal to theprescribed V_(T), the ventilator may initiate exhalation.

According to alternative embodiments, the inspiration module 214 mayprovide ventilation via a form of pressure ventilation.Pressure-targeted modes of ventilation may be provided by regulating thepressure delivered to the patient in various ways. For example, duringpressure-cycled ventilation, an end of inspiration is determined basedon monitoring the pressure delivered to the patient. According toembodiments, during pressure ventilation, the ventilator may maintainthe same pressure waveform at the mouth, P_(aw), regardless ofvariations in lung or airway characteristics, e.g., compliance and/orresistance. However, the volume and flow waveforms may fluctuate basedon lung and airway characteristics. Under pressure-cycled ventilation,upon delivering the inspiratory pressure the ventilator may initiateexhalation.

As noted above, pressure delivered to the upper airway creates apressure gradient that enables gases to flow into a patient's lungs. Thepressure from which a ventilator initiates inspiration is termed theend-expiratory pressure (EEP) or “baseline” pressure. This pressure maybe atmospheric pressure (about 0 cm H₂O), also referred to as zeroend-expiratory pressure (ZEEP). However, commonly, the baseline pressuremay be positive, termed positive end-expiratory pressure (PEEP). Amongother things, PEEP may promote higher oxygenation saturation and/or mayprevent airway collapse during exhalation.

According to still other embodiments, a combination of volume andpressure ventilation may be delivered to a patient, e.g.,volume-targeted-pressure-controlled (VC+) ventilation. In particular,VC+ ventilation may provide benefits of setting a target V_(T), whilealso allowing for monitoring variations in flow. As will be detailedfurther below, variations in flow may be indicative of various patientconditions.

Exhalation

Ventilation module 212 may further include an exhalation module 216configured to release gases from the patient's lungs according toprescribed ventilator settings. Specifically, exhalation module 216 maycorrespond to expiratory module 108 or may otherwise be associated withand/or controlling an expiratory valve for releasing gases from thepatient. By way of general overview, a ventilator may initiateexhalation based on lapse of an inspiratory time setting (T_(I)) orother cycling criteria set by the clinician or derived from ventilatorsettings (e.g., detecting delivery of prescribed V_(T) or prescribedinspiratory pressure based on a reference trajectory). Upon initiatingthe expiratory phase, exhalation module 216 may allow the patient toexhale by opening an expiratory valve. As such, exhalation is passive,and the direction of airflow, as described above, is governed by thepressure gradient between the patient's lungs (higher pressure) and theambient surface pressure (lower pressure). Although expiratory flow ispassive, it may be regulated by the ventilator based on the size of theexpiratory valve opening. According to some embodiments, the expiratoryvalve may be associated with an expiratory filter. The expiratory filtermay function to prevent mucous and other debris from passing into theventilator. However, when the expiratory filter is obstructed, e.g., dueto excess debris, mucous, etc., expiratory flow may be hindered.According to embodiments, the expiratory filter may be disposable orotherwise replaceable for eliminating excess debris, mucous, etc., thatmay increase resistance.

For a spontaneously breathing patient, expiratory time (T_(E)) is thetime from the end of inspiration until the patient triggers a nextinspiration. For a non-triggering patient, it is the time from the endof inspiration until the next mandatory inspiration based on the set RR.In some cases, however, the time required to return to the functionalresidual capacity (FRC) or resting capacity of the lungs is longer thanprovided by T_(E) (e.g., because the pulmonary time constant hasincreased due to increased resistance, the expiratory filter is cloggedhindering expiratory flow, etc.). According to embodiments, e.g., whenthe ventilator detects that resistance has increased as a result ofchanging lung conditions, various ventilatory setting may be adjusted tobetter match the time to reach FRC with the time available to reach FRC.For example, decreasing set T_(I) to thereby increase the amount of timeavailable to reach FRC. Alternatively, inspiratory pressure may bedecreased (decreasing V_(T)), resulting in less time required to reachFRC. According to alternative embodiments, e.g., when the ventilatordetects that the expiratory filter is clogged or that the patient airwaymay be obstructed by mucous, adjusting ventilatory settings may not bewarranted. Rather, the ventilator may recommend to that the clinicianchange the expiratory filter or suction the patient airway.

As may be appreciated, at the point of transition between inspirationand exhalation, the direction of airflow may abruptly change fromflowing into the lungs to flowing out of the lungs or vice versadepending on the transition. Stated another way, inspiratory flow may bemeasurable in the ventilatory circuit until P_(Peak) is reached, atwhich point flow approximates zero. Thereafter, upon initiation ofexhalation, expiratory flow is measurable in the ventilatory circuituntil the pressure gradient between the lungs and the body's surfacereaches zero (again, resulting in zero flow). However, in some cases, aswill be described further herein, expiratory flow may still be positive,i.e., measurable, at the end of exhalation (termed positiveend-expiratory flow or positive EEF). In this case, positive EEF is anindication that the pressure gradient has not reached zero or,similarly, that the patient has not completely exhaled. Thus, a positiveEEF may indicate that the T_(E) is not long enough for completeexhalation. According to some embodiments, when the ventilator detectsthat the T_(E) is not long enough for complete exhalation, theventilator may determine that the pulmonary time constant has increaseddue to increased resistance.

Ventilator Sensory Devices

The ventilatory system 200 may also include one or more distributedand/or internal sensors communicatively coupled to ventilator 202.Distributed sensors may communicate with various components ofventilator 202 e.g., ventilation module 212, internal sensors, monitormodule 218, data processing module 220, and any other suitablecomponents and/or modules. Distributed sensors may be placed in anysuitable location, e.g., within the ventilatory circuitry or otherdevices communicatively coupled to the ventilator. For example, sensorsmay be affixed to the ventilatory tubing or may be imbedded in thetubing itself. According to some embodiments, sensors may be provided ator near the lungs (or diaphragm) for detecting a pressure in the lungs.Additionally or alternatively, sensors may be affixed or imbedded in ornear wye-fitting 170 and/or patient interface 180, as described above.

Distributed sensors may further include pressure transducers that maydetect changes in circuit pressure (e.g., electromechanical transducersincluding piezoelectric, variable capacitance, or strain gauge).Distributed sensors may further include various flow sensors fordetecting airflow. For example, some flow sensors may use obstructionsto create a pressure decrease corresponding to the flow across thedevice (e.g., differential pressure pneumotachometers) and other flowsensors may use turbines such that flow may be determined based on therate of turbine rotation (e.g., turbine flow sensors). Alternatively,sensors may utilize optical or ultrasound techniques for measuringchanges in ventilatory parameters. A patient's blood parameters orconcentrations of expired gases may also be monitored by sensors todetect physiological changes that may be used as indicators to studyphysiological effects of ventilation, wherein the results of suchstudies may be used for diagnostic or therapeutic purposes. Indeed, anydistributed sensory device useful for monitoring changes in measurableparameters during ventilatory treatment may be employed in accordancewith embodiments described herein.

Ventilator 202 may further include one or more internal sensors. Similarto distributed sensors, internal sensors may communicate with variouscomponents of ventilator 202, e.g., ventilation module 212, distributedsensors, monitor module 218, data processing module 220, and any othersuitable components and/or modules. Internal sensors may employ anysuitable sensory or derivative technique for monitoring one or moreparameters associated with the ventilation of a patient. However, theone or more internal sensors may be placed in any suitable internallocation, such as, within the ventilatory circuitry or within componentsor modules of ventilator 202. For example, sensor may be coupled to theinspiratory and/or expiratory modules for detecting changes in, forexample, circuit pressure and/or flow. Specifically, internal sensorsmay include pressure transducers and flow sensors for measuring changesin circuit pressure and airflow. Additionally or alternatively, internalsensors may utilize optical or ultrasound techniques for measuringchanges in ventilatory parameters. For example, a patient's expiredgases may be monitored by internal sensors to detect physiologicalchanges indicative of the patient's condition and/or treatment, forexample. Indeed, internal sensors may employ any suitable mechanism formonitoring parameters of interest in accordance with embodimentsdescribed herein.

As should be appreciated, with reference to the Equation of Motion,ventilatory parameters are highly interrelated and, according toembodiments, may be either directly or indirectly monitored. Forexample, the distributed and internal sensors may provide raw data tothe monitor module 218. The raw data may further be provided to the dataprocessing module 220 for processing and/or deriving ventilatory data.That is, parameters may be directly monitored by one or more sensors, asdescribed above, or may be indirectly monitored by derivation accordingto the Equation of Motion or other equation, algorithm, etc.

Ventilatory Data

Ventilator 202 may further include a data processing module 220. Asnoted above, distributed sensors and internal sensors may collect dataregarding various ventilatory parameters. A ventilatory parameter refersto any factor, characteristic, or measurement associated with theventilation of a patient, whether monitored by the ventilator or by anyother device. Sensors may further transmit collected data to the monitormodule 218 and/or the data processing module 220. According toembodiments, the data processing module may 220 be configured to collectdata regarding some ventilatory parameters, to derive data regardingother ventilatory parameters, and/or to transform the collected and/orderived ventilatory data into graphical data for display to theclinician and/or other modules of the ventilatory system. According toembodiments, the collected, derived, and/or graphically transformed datamay be defined as ventilatory data. For example, data regardingend-expiratory flow (EEF), data regarding alveolar pressure P_(a) (e.g.,via a breath-hold maneuver), P_(Peak) data, P_(Plot) data, volume data,flow trace data, EEP data, etc., may be collected, derived, and/orgraphically represented by data processing module 220. Thereafter, theventilatory data may be utilized by the ventilator to detect afluctuation, either an increase or a decrease, in resistance.Furthermore, the ventilatory data may be utilized by the ventilator todetermine one or more potential causes for the fluctuation inresistance.

Furthermore, according to embodiments, ventilatory data may also includeventilator setup data. For example, ventilator setup data may includedata regarding whether the ventilator is configured to use a heated ornon-heated humidifier or a heat and moisture exchanger (HME).Furthermore, ventilator setup data may include data regarding whether aninline nebulizer or closed suction catheter is being used for thepatient. Indeed, ventilator setup data may include any data regardingthe configuration of the ventilator, ventilator circuitry, patientinterface, etc., that may be useful for characterizing a detectedfluctuation in resistance to determine one or more potential causes forthe fluctuation in resistance. For example, ventilator setup data may beuseful in determining whether condensate is likely to accumulate in thepatient circuit, etc.

Upon detecting a fluctuation in resistance and one or more potentialcauses for the fluctuation, the ventilator may determine one or morerecommendations for mitigating the fluctuation in resistance based on,inter alia, ventilatory data, prescribed ventilatory settings, patientdata, and/or any other suitable protocol, formula, equation, etc.

Flow Data

For example, according to embodiments, data processing module 220 may beconfigured to monitor inspiratory and expiratory flow. Flow may bemeasured by any appropriate, internal or distributed device or sensorwithin the ventilatory system. As described above, flow sensors may beemployed by the ventilatory system to detect circuit flow. However, anysuitable device either known or developed in the future may be used fordetecting airflow in the ventilatory circuit. Data processing module 220may be further configured to plot monitored flow data graphically viaany suitable means. For example, according to embodiments, flow data maybe plotted versus time (flow waveform), versus volume (flow-volumeloop), or versus any other suitable parameter as may be useful to aclinician.

As may be appreciated, flow decreases as resistance increases, making itmore difficult to pass gases into and out of the lungs (i.e.,F=P_(t)/R). For example, when a patient is intubated, i.e., havingeither an endotracheal or a tracheostomy tube in place, resistance maybe increased as a result of the smaller diameter of the tube over apatient's natural airway. In addition, increased resistance may beobserved in patients with obstructive disorders, such as COPD, asthma,etc. Higher resistance may necessitate, inter alia, a higher inspiratorytime setting (T_(I)) for delivering a prescribed pressure or volume ofgases, a higher flow setting for delivering prescribed pressure orvolume, a lower respiratory rate resulting in a higher expiratory time(T_(E)) for complete exhalation of gases, etc. According to embodiments,an evaluation of a flow trace and/or an evaluation of end-expiratoryflow (EEF) may be used to detect an increase in resistance, as describedfurther herein.

Pressure Data

According to embodiments, data processing module 220 may be configuredto monitor pressure. Pressure may be measured by any appropriate,internal or distributed device or sensor within the ventilatory system.For example, pressure may be monitored by proximal electromechanicaltransducers connected near the airway opening (e.g., on the inspiratorylimb, expiratory limb, at the patient interface, etc.). Alternatively,pressure may be monitored distally, at or near the lungs and/ordiaphragm of the patient. As may be appreciated, an increase intransairway pressure may be indicative of an increase in resistance,while a decrease in transairway pressure may be indicative of andecrease in resistance (i.e., R=P_(t)/F)

Data processing module 220 may be further configured to graphically plotmonitored pressure data via any suitable means. For example, accordingto embodiments, pressure data may be plotted versus time (pressurewaveform), versus volume (pressure-volume loop or PV loop), or versusany other suitable parameters as may be useful to a clinician. Accordingto embodiments, PV loops may provide useful clinical and diagnosticinformation to clinicians regarding the resistance or compliance of apatient. Specifically, upon comparing PV loops from successive breaths,an increase in resistance may be detected when successive PV loopsshorten and widen over time. That is, at constant pressure, less volumeis delivered to the lungs when resistance is increasing, resulting in ashorter, wider PV loop. According to alternative embodiments, a PV loopmay provide a visual representation, in the area between the inspiratoryplot of pressure vs. volume and the expiratory plot of pressure vs.volume, which is indicative of compliance. Further, PV loops may becompared to one another to determine whether compliance has changed.Additionally or alternatively, optimal compliance may be determined.That is, optimal compliance may correspond to the dynamic compliancedetermined from a PV loop during a recruitment maneuver, for example.

Volume Data

According to embodiments, data processing module 220 may be configuredto derive volume via any suitable means. For example, as describedabove, during volume ventilation, a prescribed V_(T) may be set fordelivery to the patient. The actual volume delivered may be derived bymonitoring the inspiratory flow over time (i.e., V=F*T). Stateddifferently, integration of flow over time will yield volume. Accordingto embodiments, V_(T) is completely delivered upon reaching T_(I).Similarly, the expiratory flow may be monitored such that expired tidalvolume (V_(TE)) may be derived. That is, under ordinary conditions, uponreaching the T_(E), the prescribed V_(T) delivered should be completelyexhaled and FRC should be reached. However, under some conditions T_(E)is inadequate for complete exhalation and FRC is not reached. Dataprocessing module 220 may be further configured to graphically plotderived volume data via any suitable means. For example, according toembodiments, volume data may be plotted versus time (volume waveform),versus flow (flow-volume loop or FV loop), or versus any other suitableparameter as may be useful to a clinician.

Resistance Fluctuation Detection

Ventilator 202 may further include resistance detection module 222.According to embodiments, resistance detection module 222 may evaluate,inter alia, the ventilatory data to detect a fluctuation in resistance.For example, based on PBW and/or other patient data, the resistancedetection module 22 may identify a maximum resistance threshold and aminimum resistance threshold (e.g., based on clinician input, astandardized protocol, institutional protocol, etc.). According toembodiments, the maximum and minimum resistance thresholds may define arange about a particular patient's measured and/or derived resistance.That is, for a patient exhibiting elevated resistance (e.g., a patientdiagnosed with ARDS or COPD), the maximum and minimum resistancethresholds may be higher than for a patient exhibiting normalresistance.

The resistance detection module 222 may further trend resistance valuesfor the patient via any suitable means. “Trending,” as used herein,means collecting and/or deriving data over a plurality of breaths (or atpredetermined intervals of time). For example, according to embodiments,the resistance detection module 222 may trend resistance by evaluating aplurality of successive PV loops. According to alternative embodiments,the resistance detection module 222 may trend resistance by trendingflow data at a constant pressure (e.g., during successive maneuvers). Inthis case, where other variables are known and/or constant, if flowdecreases over time at constant pressure, resistance is increasing;whereas if flow is increasing over time at constant pressure, resistanceis decreasing (i.e., R=P_(t)/F). According to alternative embodiments, apositive end expiratory flow may be indicative of increased resistancewhere expiratory time (T_(E)) is not sufficient to reach FRC. Accordingto still other embodiments, resistance may be trended via any suitablemeans.

The trended resistance may be compared to the identified maximum andminimum threshold values to detect a fluctuation in resistance. When thetrended resistance data breaches the maximum threshold value, theresistance detection module 222 may detect an increase in resistance.When the trended resistance data breaches the minimum threshold value,the resistance detection module 222 may detect a decrease in resistance.

Upon detection of a fluctuation in resistance, a potential causedetermination module 224 may identify one or more potential causes forthe fluctuation in resistance. For example, the potential causedetermination module 224 may identify whether the fluctuation inresistance is an increase or a decrease. Furthermore, the potentialcause determination module 224 may identify a location of thefluctuation in resistance. According to embodiments, the ventilator maybe configured with one or more potential causes associated with anincrease in resistance and with one or more potential causes associatedwith a decrease in resistance. Furthermore, the ventilator may beconfigured with one or more potential causes associated with a locationof the fluctuation in resistance. For example, based on a protocol,standard, or otherwise, the ventilator may be configured to associate anincrease in resistance with one or more of the following potentialcauses, among others: obstructed expiratory filter, obstructedventilatory circuit (e.g., due to condensate accumulation, kinking, orotherwise), obstructed patient airway (e.g., due to mucus plugging),changing lung conditions (e.g., ARDS-related inflammatory response,asthma-related bronchial constriction, COPD-related airway constriction,bronchial edema, bronchospasm, infection and/or fluid, etc.), patientbody position, poor internal placement of the ventilatory circuit, etc.For example, Indeed, the ventilator may be configured with any suitablenumber of potential causes associated with an increase in resistance.Furthermore, based on a protocol, standard, or otherwise, the ventilatormay be configured to associate a decrease in resistance with one or moreof the following potential causes: a leak in the ventilatory circuit,changing lung conditions (e.g., bronchial relaxation after medication,reduced infection and/or fluid, etc.), improved body position, etc. Asabove, the ventilator may be similarly configured with any suitablenumber of potential causes associated with a decrease in resistance.

According to embodiments, upon a determination that the fluctuation inresistance is an increase or a decrease and identification of one ormore potential causes for the increase or decrease in resistance, alikelihood determination module 226 may be configure to determine arelative likelihood for each of the one or more identified potentialcauses. For example, likelihood determination module 226 may determine arelative likelihood for each of the one or more identified potentialcauses based on ventilatory data, patient data, sensory data, algorithmsor other probability computations, etc. The likelihood determinationmodule 226 may further rank or otherwise organize the one or moreidentified potential causes according to their relative likelihoods. Forexample, according to embodiments, the likelihood determination module226 may be configured to determine a relative likelihood of one or moreidentified potential causes based on a location of the fluctuation inresistance. For example, when increased resistance was detected in theexpiratory limb, it may be more likely that condensate accumulation inthe ventilatory circuit or a clogged expiratory filter may be potentialcauses. Furthermore, according to embodiments, the likelihooddetermination module 226 may be configured to determine a relativelikelihood that the expiratory filer is obstructed based on one or moreof the following (among others): data from a sensory device at or nearthe expiratory value, an evaluation of when the expiratory filter waslast replaced, an evaluation of expiratory flow, etc. That is, accordingto embodiments, the ventilator may detect increased resistance in theexpiratory limb of the ventilatory circuit indicative of a cloggedexpiratory filter.

According to embodiments, the ventilator may be further configured todetermine a relative likelihood that the patient circuit is occluded.For example, an abrupt increase in resistance may be indicative of aventilatory circuit that is kinked or otherwise temporarily occluded. Incontrast, a gradual increase in resistance may be indicative of mucousplugging (among other causes). For example, the ventilator may detectmucous plugging in the patient's airway via one or more distributedsensory devices, a length of time since the patient airway was lastsuctioned, increased resistance to delivered flow to the patient, etc.According to other embodiments, the ventilator may be configured todetermine a relative likelihood that decreased resistance is due to aleak in the ventilatory circuit. For instance, ventilator may evaluateone or more of the following (among others): whether delivered volume isless than the expired volume, data collected by distributed sensorsalong the ventilatory circuit, treaded flow data, etc.

According to some embodiments, the likelihood determination module 226may further evaluate patient data and/or a patient diagnosis todetermine whether certain changed lung conditions are like responsiblefor a fluctuation in resistance. For example, if patient data indicatesthat the patient is asthmatic, the ventilator may determine a higherrelative likelihood that bronchial constriction is a potential cause foran increase in resistance. In contrast, if the patient has beendiagnosed with ARDS, the ventilator may determine a higher relativelikelihood that an increase in inflammation of the airways is apotential cause for the increase in resistance. Alternatively, if thepatient was diagnosed with pneumonia, the ventilator may determine ahigher relative likelihood that a reduction in infection and/or fluid inthe patient's lungs is a potential cause for a decrease in resistance(or that an increase in infection and/or fluid in the lungs is apotential cause for an increase in resistance). Indeed, each identifiedpotential cause may be associated with a relative likelihood based onany available ventilatory data, sensory data, patient data, etc.,retrieved by the ventilator. According to embodiments, the ventilatormay determine that more than one potential cause may have a same orsimilar relative likelihood for causing an increase or a decrease inresistance.

According to some embodiments, the ventilator may display each of theone or more identified potential causes to the clinician. According toother embodiments, the ventilator may only display a subset of the oneor more identified potential causes, e.g., only potential causes havinghigher relative likelihoods. The ventilator may be configured todetermine and display the subset of identified potential causes via anysuitable means. For example, the ventilator may be configured to displaya predetermined number of the most likely potential causes, e.g., thethree most likely potential causes. In this case, the ventilator willdisplay the three most likely potential causes of three identifiedpotential causes, of five identified potential causes, or of tenidentified potential causes. As may be appreciated, any number of themost likely potential cause may be pre-configured, selected, orotherwise designated for display. According to alternative embodiments,the ventilator may be configured to display a most likely percentage ofidentified potential causes. For example, the ventilator may beconfigured to display the most likely 40% of potential causes. In thiscase, the most like of 4 of 10 identified potential causes, the mostlikely 2 of 5 identified potential causes, etc. (here, the ventilatormay be further configured to round up or down to the nearest wholenumber of potential causes for display). According to still otherembodiments, each potential cause may be designated with a likelihoodprobability upon evaluation of ventilatory data, patient data,statistical analyses, etc. (e.g., a likelihood probability between 1 and100) and the ventilator may be configured to display only thosepotential causes with a likelihood probability greater than some number(e.g., a likelihood probability of 50 or more). Indeed, any suitablemethod for ranking, organizing, or otherwise identifying and displayingone or more likely potential causes for an increase or a decrease inresistance may be employed within the spirit of the present disclosure.

Prompt Generation

Ventilator 202 may further include a prompt module 228. The promptmodule 228 may provide a prompt notifying a clinician of a detectedincrease or decrease in resistance. According to some embodiments, theprompt may be provided in a hierarchical format such that an initialprompt is displayed that provides a notification to the clinician thatan increase or a decrease in resistance has been detected. The initialprompt may further provide an indication of the one or more identifiedpotential causes for the increase or decrease in resistance.Alternatively, the initial prompt may only display a subset of theidentified potential causes, i.e., the most likely potential causes.According to other embodiments, the initial prompt may only display anotification that an increase or a decrease in resistance has beendetected and the one or more potential causes may be displayed on anexpanded prompt.

According to embodiments, the prompt module 228 may provide the initialprompt as a tab, banner, dialog box, or other suitable type of display.The initial prompt may be provided along a border of the graphical userinterface, near an alarm display or bar, or in any other suitablelocation. A shape and size of the initial prompt may further beoptimized for easy viewing with minimal interference to otherventilatory displays. The initial prompt may be further configured witha combination of icons and text such that the clinician may readilyidentify whether resistance has increased or decreased and, optionally,one or more potential causes for the increase or decrease in resistance.According to some embodiments, the initial prompt may display only oneor more potential causes having a higher relative likelihood for causingthe increase or decrease in resistance.

According to further embodiments, the prompt module 228 may provide anexpanded prompt via any suitable means. For example, the expanded promptmay be selectably activated via any suitable means and may display theone or more identified potential causes and/or one or morerecommendations for mitigating the increase or decrease in resistance.The expanded prompt may further be provided adjacent to the prompt(i.e., initial prompt) along a border of the graphical user interface,near an alarm display or bar, or in any other suitable location. Theshape and size of the expanded prompt may further be optimized for easyviewing with minimal interference to other ventilatory displays.

Prompt module 228 may also provide the initial prompt and/or expandedprompt as a partially transparent window or format. The transparency mayallow for the initial prompt and/or expanded prompt to be displayed suchthat normal ventilator GUI and ventilatory data may be visualized behindthe prompts. This feature may be particularly useful for displaying theexpanded prompt. The initial prompt and/or expanded prompt may furtherbe displayed in areas of the user interface that are either blank orthat cause minimal distraction from the ventilatory data and othergraphical representations provided by the GUI. However, upon selectiveexpansion of an initial prompt, data and graphs may be at leastpartially obscured. As a result, prompt module 228 may provide theexpanded prompt such that it is partially transparent.

The prompt module 228 may further include a notification module 230. Thenotification module 230 may identify a fluctuation in resistance via anysuitable means. For example, the notification module 230 may be incommunication with the resistance detection module 222, the monitormodule 218, the data processing module 220, and/or any other suitablemodule or sensory device to identify that a fluctuation in resistancehas been detected by the ventilator. Further, the notification module230 may identify whether the fluctuation in resistance is an increase ora decrease and a location in the ventilatory system where thefluctuation in resistance was detected. According to embodiments, thenotification module 230 may further identify one or more potentialcauses for the increase or decrease in resistance. For example, thenotification module 230 may be in communication with the potential causedetermination module 224 or any other suitable module or sensory device.According to further embodiments, the notification module 230 mayidentify a relative likelihood of each of the one or more identifiedpotential causes. For example, the notification module 230 may be incommunication with the likelihood determination module 226 or any othersuitable module or sensory device. According to embodiments, thenotification module 230 may further provide an indication of theincrease or decrease in resistance to the prompt module 228 for displayon a prompt. According to additional embodiments, the notificationmodule 230 may further provide an indication of the one or morepotential causes for the increase or the decrease in resistance, or asubset thereof, to the prompt module 228 for display on a prompt.

The prompt module 228 may further include a recommendation module 232.That is, according to embodiments, in addition to identifying one ormore potential causes for an increase or a decrease in resistance, theventilator may also determine one or more recommendations for mitigatingthe increase or decrease in resistance. For example, prompt module 228may be configured to display the one or more recommendations on a prompton user interface 204, e.g., within a window of the GUI. According toadditional embodiments, the prompt may be communicated to and/ordisplayed on a remote monitoring system communicatively coupled toventilatory system 200.

According to embodiments, the recommendation module 232 may retrieve oneor more potential causes for the increase or decrease in resistance fromthe potential cause determination module 224 or, according to someembodiments, the recommendation module 232 may retrieve only one or morepotential causes having a higher relative likelihood of causing theincrease or decrease in resistance from the likelihood determinationmodule 226. As may be appreciated, the ventilator may be configured toassociate some potential causes for an increase or a decrease inresistance with one or more appropriate recommendations for mitigatingthe increase or decrease in resistance. In contrast, for other potentialcauses, it may not be appropriate or necessary to mitigate the increaseor decrease in resistance (e.g., where a decrease in resistance isdetected upon administration of medication for bronchial constriction).

According to embodiments, the recommendation module 232 may beconfigured to determine one or more appropriate recommendations formitigating an increase or a decrease in resistance based on anevaluation of ventilatory data, patient data, sensory data, currentventilatory settings, and any suitable protocol, equation, etc. Forexample, the ventilator may evaluate each potential cause (or each ofthe more likely potential causes) in light of data known to theventilator in order to determine one or more recommendations formitigating the increase or decrease in resistance. That is, if theventilator determines that it is relatively likely that a dirtyexpiratory filter caused an increase in resistance, the ventilator maydetermine that it is appropriate to recommend changing the expiratoryfilter. In contrast, if the ventilator determines that it is relativelylikely that a kink or temporary occlusion of the ventilatory circuitcaused an increase in resistance, the ventilator may determined that itis appropriate to recommend checking the ventilatory circuit forkinking. Alternatively, if the ventilator determines that it isrelatively likely that bronchial constriction is a cause for an increasein resistance (e.g., for an asthmatic patient), the ventilator maydetermine that it is appropriate to recommend administration ofmedication to the patient (here, the ventilator may be furtherconfigured to evaluate the last time that medication was administeredprior to determining the appropriate recommendation). In contrast, ifthe patient has been diagnosed with COPD, the ventilator may determinethat it is appropriate to recommend increasing PEEP in order to promotebronchial patency.

As specified above, in some cases a recommendation may not be warranted.For example, if the ventilator determines that administration ofmedication is a likely cause of a decrease in resistance, the ventilatormay not provide a recommendation but may merely notify the clinician ofthe decreased resistance. Similarly, if the ventilator senses a decreasein resistance following suctioning of the patient airway, the ventilatormay merely notify the clinician of the decrease rather than offering arecommendation for mitigating the decrease in resistance. As may beappreciated, the one or more recommendations may be based on a varietyof considerations, including whether the resistance increased ordecreased, on potential causes for the increase or decrease inresistance, and on available ventilatory data, patient data, sensorydata, and any suitable protocol, equation, etc. Indeed, as should beappreciated, any number of appropriate recommendations may be determinedbased on each of a plurality of potential causes for the increase ordecrease in resistance.

In order to accomplish the various aspects of the notification and/orrecommendations display, the prompt module 228 may communicate withvarious other components and/or modules. For instance, prompt module 228may be in communication with monitor module 218, data processing module220, resistance detection module 224, potential cause determinationmodule 224, likelihood determination module 226, notification module230, recommendation module 232, and/or any other suitable module orcomponent of the ventilatory system 200. That is, prompt module 228 mayreceive ventilatory data, sensory data, and information regarding anysuitable protocol, equation, etc. Further, according to someembodiments, the prompt module 228 may have access to patient data,including a patient's diagnostic information (e.g., regarding whetherthe patient has ARDS, COPE, asthma, emphysema, or any other disease,disorder, or condition).

According to embodiments, upon viewing an initial prompt and/or expandedprompt in response to detection of an increase or decrease inresistance, the initial prompt and/or expanded prompt may be clearedfrom the graphical user interface.

Methods of Prompt Generation

FIG. 3 is a flow chart illustrating an embodiment of a method forissuing a prompt upon detecting an increase or a decrease in resistance.

As should be appreciated, the particular steps and methods describedherein are not exclusive and, as will be understood by those skilled inthe art, the particular ordering of steps as described herein is notintended to limit the method, e.g., steps may be performed in differingorder, additional steps may be performed, and disclosed steps may beexcluded without departing from the spirit of the present methods.

Method 300 begins with an initiate ventilation operation 302. Initiateventilation operation 302 may further include various additionaloperations. For example, initiate ventilation operation 302 may includereceiving one or more ventilatory settings associated with ventilationof a patient. As such, the ventilatory settings and/or input receivedmay include, inter alia, an inspiratory pressure (or target inspiratorypressure), a tidal volume (V_(T)), a respiratory rate (RR), an I:Eratio, a % O₂, etc. Additionally, during ventilation, ventilatorysetting may be adjusted and accepted. In addition, during initiateventilation operation 302, patient data may be received. Patient datamay refer to any data particular to a patient, for example, a predictedor ideal body weight (PBW or IBW), a patient diagnosis, a patient age, apatient disability, a patient post-operative condition, etc. A patientdiagnosis may include, inter alia, ARDS, COPD, emphysema, asthma, etc.Upon initiating ventilation, the ventilator may further monitorventilatory parameters and collect and/or derive ventilatory data.

At retrieve operation 304, the ventilator may retrieve ventilatory data,patient data, etc. The ventilatory data may include data collected whilemonitoring various ventilatory parameters, including volume, pressure,flow, etc. The ventilatory data may further include data that iscalculated or otherwise derived from the collected data, e.g., via theEquation of Motion or otherwise. For example, resistance may becalculated or otherwise derived from collected data such as flow,pressure, or volume (e.g., R=P_(t)/F; R=τ*ΔP/ΔV; etc.) Furthermore,resistance may be derived at over a plurality of breaths or atpredetermined intervals of time. The patient data may include, interalia, any data particular to a patient as described above.

At identify operation 306, the ventilator may identify a maximumresistance threshold and a minimum resistance threshold. For example,the maximum resistance threshold and a minimum resistance threshold maybe based on PBW and/or other patient data (e.g., based on clinicianinput, a standardized protocol, institutional protocol, etc.). Accordingto alternative embodiments, the maximum and minimum resistancethresholds may be defined for a particular patient. That is, based on aninitial calculation of a particular patient's resistance, the maximumthreshold may be set at a certain amount or percentage above the initialcalculation and the minimum threshold may be set at a certain amount orpercentage below the initial calculation. In this case, for a patientexhibiting elevated resistance (e.g., a patient diagnosed with ARDS orCOPD), the maximum and minimum resistance thresholds may be higher thanfor a patient exhibiting normal resistance. According to alternativeembodiments, the maximum and minimum resistance thresholds may be basedat least in part on a patient diagnosis (e.g., based on clinician input,a standardized protocol, institutional protocol, etc.). In this case, aswith the example above, the maximum and minimum resistance thresholdsmay be higher for a patient diagnosed with COPD than for a patientexhibiting normal resistance.

At trend operation 308, the ventilator may trend resistance. Asdescribed above, according to embodiments, the ventilator may trendresistance by evaluating a plurality of successive PV loops. Asdescribed above, an increase in resistance may be detected whensuccessive PV loops shorten and widen over time. That is, at constantpressure, less volume is delivered to the lungs when resistance isincreasing, resulting in a shorter, wider PV loop. According toalternative embodiments, the ventilator may trend resistance by trendingflow data at a constant pressure (e.g., during successive maneuvers). Inthis case, where other variables are known and/or constant, if flowdecreases over time at constant pressure, resistance is increasing;whereas if flow is increasing over time at constant pressure, resistanceis decreasing (i.e., R=P_(t)/F). According to alternative embodiments, apositive end expiratory flow may be indicative of increased resistancewhere expiratory time (T_(E)) is not sufficient to reach FRC. Accordingto other embodiments, calculated values for resistance may be trendedover a period of time or over a number of breaths. According to stillother embodiments, resistance may be trended via any suitable means.According to alternative embodiments, the ventilator may trendresistance values associated with a location. For example, theventilator may monitor and trend resistance at or near the expiratoryvalve, within the expiratory limb or the inspiratory limb of theventilatory circuit, within the patient airway, etc. According to someembodiments, different maximum and minimum resistance thresholds mayapply based on the monitored location.

At determination operation 310, the ventilator may compare the trendedresistance with the maximum threshold. If the trended resistancebreaches the maximum threshold, the ventilator may detect an increase inresistance at detect operation 312. According to embodiments, theventilator may further associate the increase in resistance with alocation, e.g., patient airway, expiratory limb, etc.

At determination operation 314, the ventilator may compare the trendedresistance with the minimum threshold. If the trended resistancebreaches the minimum threshold, the ventilator may detect a decrease inresistance at detect operation 316. According to embodiments, theventilator may further associate the decrease in resistance with alocation, e.g., patient airway, expiratory limb, etc.

At issue prompt operation 318, the ventilator may issue a promptproviding a notification that an increase or a decrease in resistancewas detected by any suitable means. For example, the ventilator maygenerate an alert or other notification in text form. For example, thenotification may provide: “Increased Resistance Detected” or “DecreasedResistance Detected.” According to alternative embodiments, the promptmay provide a notification via an abbreviated alert, an icon, or anyother suitable method of notifying the clinician that an increase or adecrease in resistance was detected by the ventilator. As describedabove, the prompt may be displayed by any suitable means in any suitablelocation on the ventilator or a remote monitor. For example, the promptmay be displayed as a tab, banner, dialog box, or other suitable type ofdisplay, along a border of the graphical user interface, near an alarmdisplay or bar, or in any other suitable location. The prompt mayfurther be displayed in areas of the user interface that are eitherblank or that cause minimal distraction from the ventilatory data andother graphical representations provided by the GUI. The prompt may beprovided in a transparent form, or otherwise, for minimizingdistraction, and may be cleared upon clinician viewing.

FIG. 4 is a flow chart illustrating an embodiment of a method forissuing a prompt upon determining one or more potential causes for anincrease or a decrease in resistance.

As should be appreciated, the particular steps and methods describedherein are not exclusive and, as will be understood by those skilled inthe art, the particular ordering of steps as described herein is notintended to limit the method, e.g., steps may be performed in differingorder, additional steps may be performed, and disclosed steps may beexcluded without departing from the spirit of the present methods.

Method 400 begins with detect fluctuation operation 402, wherein theventilator detects a fluctuation in resistance, either an increase or adecrease, as described above with reference to method 300.

At determination operation 404, the ventilator may determine whether thefluctuation in resistance is an increase, as described above withreference to method 300.

Upon a determination that there was an increase in resistance, themethod may proceed to retrieve operation 406. At retrieve operation 406,the ventilator may retrieve ventilatory data, patient data, and/or anyother data, equation, protocol, standard, etc., as described withreference to operation 304. Furthermore, at identify operation 408, theventilator may identify one or more potential causes for the increase inresistance. As described above, the ventilator may be configured withone or more potential causes associated with an increase in resistance.For example, based on a protocol, standard, or otherwise, the ventilatormay be configured to associate an increase in resistance with one ormore of the following potential causes, among others: obstructedexpiratory filter, obstructed ventilatory circuit (e.g., due tocondensate accumulation, kinking, or otherwise), obstructed patientairway (e.g., due to mucous plugging), changing lung conditions (e.g.,asthma-related bronchial constriction, COPD-related airway constriction,ARDS-related inflammatory response, bronchial edema, bronchospasm,infection and/or fluid, etc.), poor patient body position, improperinternal placement of the ventilatory circuit, etc. Indeed, theventilator may be configured with any suitable number of potentialcauses associated with an increase in resistance.

Upon a determination that there was not an increase in resistance, themethod may proceed to detect operation 410. At detect operation 410, theventilator may determine that a decrease in resistance was detected.

Upon a determination that there was a decrease in resistance, the methodmay proceed to retrieve operation 412. At retrieve operation 412, theventilator may retrieve ventilatory data, patient data, and/or any otherdata, equation, protocol, standard, etc., as described with reference tooperation 304. Furthermore, at identify operation 414, the ventilatormay identify one or more potential causes for the decrease inresistance. As described above, the ventilator may be configured withone or more potential causes associated with a decrease in resistance.For example, based on a protocol, standard, or otherwise, the ventilatormay be configured to associate a decrease in resistance with one or moreof the following potential causes: a leak in the ventilatory circuit,changing lung conditions (e.g., bronchial relaxation after medication,reduced infection and/or fluid, etc.), improved body position, etc. Asabove, the ventilator may be similarly configured with any suitablenumber of potential causes associated with a decrease in resistance.

At optional determine operation 416 (identified by dashed lines), theventilator may optionally determine a relative likelihood for each ofthe one or more identified potential causes for the increase or thedecrease in resistance, e.g., based on ventilatory data, patient data,sensory data, algorithms, statistical analyses, etc. For example,according to embodiments, the ventilator may be configured to determinea relative likelihood that the expiratory filter is obstructed based onone or more of the following (among others): data from a sensory deviceat or near the expiratory valve, an evaluation of when the expiratoryfilter was last replaced, an evaluation of expiratory flow, etc.According to some embodiments, the ventilator may detect an increase inexpiratory limb resistance indicative of a clogged expiratory filter.The ventilator may be further configured to determine a relativelikelihood that the ventilatory circuit is occluded. For example, anabrupt increase in resistance may be indicative of a ventilatory circuitthat is kinked or otherwise temporarily occluded, and if so, theventilator may be further configured to identify whether the inspiratoryor expiratory limb is occluded. In contrast, a gradual increase inresistance may be indicative of mucous plugging in the patient airway orcondensate accumulation in the ventilatory circuit. For example, theventilator may detect mucous plugging in the patient airway via one ormore distributed sensory devices, a length of time since the patientairway was last suctioned, increased resistance in the patient airway,etc. Alternatively, the ventilator may detect condensate accumulation inthe ventilatory circuit via one or more distributed sensory device, alength of time since the ventilatory circuit was drained of condensate,a type of humidifier utilized (e.g., heated or not), etc. As may beappreciated, the ventilator may be configured to determine a relativelikelihood for each of the one or more potential causes for the increaseor the decrease in resistance via any suitable means.

According to some embodiments, the ventilator may also evaluate patientdata, including a patient diagnosis, to determine relative likelihoodsfor the one or more identified potential causes. For example, if thepatient data indicates that the patient is asthmatic, the ventilator maydetermine a higher relative likelihood that bronchial constriction is apotential cause for an increase in resistance. In contrast, if thepatient has been diagnosed with ARDS, the ventilator may determine ahigher relative likelihood that an increase in inflammatory response isa potential cause for the increase in resistance. Alternatively, if thepatient was diagnosed with pneumonia, the ventilator may determine ahigher relative likelihood that a reduction in infection and/or fluid inthe patient's lungs is a potential cause for a decrease in resistance(or that an increase in infection and/or fluid in the lungs is apotential cause for an increase in resistance). Indeed, each identifiedpotential cause may be associated with a relative likelihood based onthe specific ventilatory data, sensory data, patient data, etc.,retrieved by the ventilator. According to embodiments, the ventilatormay determine that more than one potential cause may have a same orsimilar relative likelihood for causing an increase or a decrease inresistance.

At optional determine operation 418 (identified by dashed lines), theventilator may optionally rank or otherwise organize the one or moreidentified potential causes according to their relative likelihoods. Forexample, based on algorithms, statistical analyses, probability theorem,or otherwise, the ventilator may determine a probability that each ofthe one or more identified potential causes led to the increase or thedecrease in resistance. For instance, according to embodiments, eachpotential cause may be designated with a likelihood probability uponevaluation of ventilatory data, patient data, computations, etc. (e.g.,a likelihood probability between 1 and 100). According to alternativeembodiments, the ventilator may simply rank each of the one or moreidentified potential causes according to their relative likelihoods,e.g., for 5 identified potential causes, the ventilator may rank eachpotential cause from 1, most likely, to 5, least likely. For potentialcauses that are determined to have a statistically equivalentlikelihood, the ventilator may assign the same ranking. Indeed, theventilator may be configured to rank or organize each of the identifiedpotential causes for the increase or the decrease in resistance via anysuitable means.

At issue prompt operation 420, the ventilator may issue a promptdisplaying one or more potential causes for the increase or decrease inresistance via any suitable means. For example, the prompt may provide:“Increased Resistance Likely Due to Clogged Expiratory Filter,”“Increased Resistance Likely Due to Bronchial Constriction,” or“Decreased Resistance Likely Due to Response to Bronchodilator Therapy,”etc. According to embodiments, the prompt may display one or more of theidentified potential causes but less than all of the identifiedpotential causes for the increase or the decrease in resistance. Forexample, according to some embodiments, the ventilator may display onlya most likely potential cause on the prompt. For example, where theventilator determines that an increase in resistance may be due tocondensate accumulation in the ventilatory circuit or to a cloggedexpiratory filter, but where condensate accumulation is more likely, theprompt may display only: “Increase Resistance Detected, CondensateAccumulation Likely.” According to alternative embodiments, theventilator may be configured to display a predetermined number of themost likely potential causes, e.g., the three most likely potentialcauses. According to still alternative embodiment, the ventilator may beconfigured to display a most likely percentage of identified potentialcauses, e.g., the most likely 40% of potential causes. According tostill alternative embodiments, the ventilator may be configured todisplay only those potential causes with a likelihood probabilitygreater than some number (e.g., a likelihood probability of 50 or more).Indeed, the ventilator may be configured to display the one or morepotential causes for the increase or decrease in resistance, or a subsetthereof, according to any suitable method. According to at least someembodiments, the ventilator may determine one or more potential causesfor the increase or decrease in resistance but may not display the oneor more potential causes to the clinician.

As described above, the prompt may be displayed by any suitable means inany suitable location on the ventilator or a remote monitor. Forexample, the prompt may be displayed as a tab, banner, dialog box, orother suitable type of display, along a border of the graphical userinterface, near an alarm display or bar, or in any other suitablelocation. The prompt may further be displayed in areas of the userinterface that are either blank or that cause minimal distraction fromthe ventilatory data and other graphical representations provided by theGUI. The prompt may be provided in a transparent form, or otherwise, forminimizing distraction, and may be cleared upon clinician viewing.

According to some embodiments, the ventilator may display the one ormore potential causes for the increase or decrease in resistance, or asubset thereof, on an expanded prompt. For example, the ventilator maynotify the clinician of an increase or a decrease in resistance on aninitial prompt. The initial prompt may provide an icon or otherselectable control such that upon clinician selection the one or morepotential causes for the increase or decrease in resistance may bedisplayed on an expanded prompt. The expanded prompt may further beprovided adjacent to the initial prompt along a border of the graphicaluser interface, near an alarm display or bar, or in any other suitablelocation. The shape and size of the expanded prompt may further beoptimized for easy viewing with minimal interference to otherventilatory displays. The initial prompt and/or expanded prompt may beprovided in a transparent form, or otherwise, for minimizingdistraction, and may be cleared upon clinician viewing.

FIG. 5 is a flow chart illustrating an embodiment of a method forissuing a prompt upon determining one or more recommendations formitigating an increase or a decrease in resistance.

As should be appreciated, the particular steps and methods describedherein are not exclusive and, as will be understood by those skilled inthe art, the particular ordering of steps as described herein is notintended to limit the method, e.g., steps may be performed in differingorder, additional steps may be performed, and disclosed steps may beexcluded without departing from the spirit of the present methods.

Method 500 begins with detect operation 502, wherein the ventilatordetects a fluctuation (either an increase or a decrease) in resistance,as described above with reference to method 300.

At retrieve operation 504, the ventilator may retrieve ventilatory data,patient data, and/or any other data, equation, protocol, standard, etc.,as described with reference to operation 304.

At identify operation 506, the ventilator may identify one or morepotential causes for the fluctuation in resistance, as described abovewith reference to method 400.

At determine operation 508, the ventilator may determine one or morerecommendations for mitigating the fluctuation in resistance. Accordingto embodiments, based on each of the one or more potential causes andthe retrieved ventilatory data, patient data, etc., the ventilator maydetermine one or more appropriate recommendations. For example, if oneof the identified potential causes for an increase in resistance is aclogged expiratory filter, the ventilator may determine an appropriaterecommendation for mitigating the increased resistance includes checkingand/or changing the expiratory filter. Alternatively, if one of theidentified potential causes for an increase in resistance is improperpatient position, the ventilator may determine an appropriaterecommendation for mitigating the increased resistance includesrepositioning the patient. Alternatively still, if one of the identifiedpotential causes for an increase in resistance is bronchialconstriction, the ventilator may evaluate available ventilatory data,patient data, etc., and may determine that the patient is diagnosed withasthma and that an appropriate recommendation for mitigating theincreased resistance includes suggesting administration of abronchodilator. Alternatively still, if one of the identified potentialcauses for an increase in resistance is an inflammatory response, theventilator may evaluate available ventilatory data, patient data, etc.,and may determine that the patient is diagnosed with ARDS and that anappropriate recommendation for mitigating the increased resistanceincludes suggesting bronchodilator therapy or suctioning the patientairway. Alternatively still, if one of the identified potential causesfor a decrease in resistance is a leak in the ventilatory circuit, theventilator may determine an appropriate recommendation for mitigatingthe decreased resistance includes suggesting checking the ventilatorycircuit. As should be appreciated, any number of appropriaterecommendations for mitigating a fluctuation in resistance may bedetermined based on a particular potential cause of the fluctuation andavailable ventilatory data, patient data, etc. Furthermore, according toembodiments, one or more recommendations may be determined for each ofthe identified one or more potential causes for a fluctuation inresistance.

At issue prompt operation 510, the ventilator may issue a promptdisplaying the one or more recommendations for mitigating thefluctuation in resistance via any suitable means. For example, therecommendation may provide: “Increased Resistance Detected, CheckExpiratory Filer,” “Increased Resistance Detected, ConsiderBronchodilator Therapy,” “Increased Resistance Detected, ConsiderSuctioning Patient Airway,” or “Decreased Resistance Detected, SuggestChecking Ventilatory Circuit for Leak,” etc. As described above, theprompt may be displayed by any suitable means in any suitable locationon the ventilator or a remote monitor. For example, the prompt may bedisplayed as a tab, banner, dialog box, or other suitable type ofdisplay, along a border of the graphical user interface, near an alarmdisplay or bar, or in any other suitable location. The prompt mayfurther be displayed in areas of the user interface that are eitherblank or that cause minimal distraction from the ventilatory data andother graphical representations provided by the GUI. The prompt may beprovided in a transparent form, or otherwise, for minimizingdistraction, and may be cleared upon clinician viewing.

According to some embodiments, the ventilator may display the one ormore recommendations for mitigating the increase or decrease inresistance on an expanded prompt. That is, according to embodiments, theventilator may notify the clinician of an increase or a decrease inresistance on an initial prompt. For example, the notification maydisplay: “Increased Resistance Detected” or “Decreased ResistanceDetected.” The initial prompt may provide an icon or other selectablecontrol such that upon clinician selection the one or morerecommendations for mitigating the increase or decrease in resistancemay be displayed on an expanded prompt. According to embodiments, theone or more recommendations for mitigating the increase or decrease inresistance may be displayed along with each of one or more potentialcauses (or a subset thereof) on the expanded prompt. According toalternative embodiments, only the one or more recommendations formitigating the increase or the decrease in resistance may be displayedon the expanded prompt. According to some embodiments, a recommendationassociated with a more likely potential cause may be displayed as aprimary recommendation and a recommendation associated with a lesslikely potential cause may be displayed as a secondary recommendation.For example, the initial prompt may display “Increased ResistanceDetected” or “Increased Resistance Detected, Condensate AccumulationLikely,” and, upon selection of an expand icon or otherwise, theexpanded prompt may display a primary recommendation of: “ConsiderDraining Condensate from Circuit” and a secondary recommendation of:“Consider Changing Expiratory Filter.”

The expanded prompt may be provided adjacent to the initial prompt alonga border of the graphical user interface, near an alarm display or bar,or in any other suitable location. The shape and size of the expandedprompt may further be optimized for easy viewing with minimalinterference to other ventilatory displays. The initial prompt and/orexpanded prompt may be provided in a transparent form, or otherwise, forminimizing distraction, and may be cleared upon clinician viewing.

Ventilator GUI Display of Prompt

FIG. 6 is an illustration of an embodiment of a graphical user interfacedisplaying a prompt comprising an increased resistance notification anda recommendation for mitigating the increased resistance.

Graphical user interface 600 may display various monitored and/orderived data to the clinician during ventilation of a patient. Inaddition, graphical user interface 600 may display various messages tothe clinician (e.g., alarm messages, etc.). Specifically, graphical userinterface 600 may display a prompt as described herein.

According to embodiments, the ventilator may monitor and evaluatevarious ventilatory parameters based on one or more predeterminedthresholds to detect a fluctuation in resistance. In some cases, theventilator may determine that fluctuation in resistance is a decrease inresistance. In other cases, the ventilator may determine that thefluctuation in resistance is an increase in resistance. For example, adetection of positive end-expiratory flow (EEF) may be indicative of anincrease in resistance. As illustrated, a flow waveform may be generatedand displayed by the ventilator on graphical user interface 600. Asfurther illustrated, the flow waveform may be displayed such thatinspiratory flow 602 is represented in a different color (e.g., green)than expiratory flow 600 (e.g., yellow). Although expiratory flow maypreferably approximate zero at the end of expiration, in some instancesEEF may not reach zero before inspiration begins, as illustrated bypositive EEF 606. According to embodiments, positive EEF may beidentified by a positive EEF icon 608, or other identifier, such that aclinician may readily identify positive EEF on the flow waveform.Additionally or alternatively, the flow waveform may be frozen for aperiod of time such that the clinician may be alerted as to the positionin time of the incidence of positive EEF along the flow waveform.According to some embodiments, when positive EEF is detected, theventilator may make a determination that resistance has increased byevaluating additional ventilatory data such as trended resistance,evaluation of PV loops, etc.

Upon a determination that resistance has increased, the graphical userinterface 600 may display a prompt, e.g., prompt 610.

According to embodiments, prompt 610 may be displayed in any suitablelocation such that a clinician may be alerted regarding the detectedincrease in resistance, but while allowing other ventilatory displaysand data to be visualized substantially simultaneously. As illustrated,prompt 610 is presented as a bar or banner across an upper region of thegraphical user interface 600. However, as previously noted, prompt 610may be displayed as a tab, icon, button, banner, bar, or any othersuitable shape or form. Further, prompt 610 may be displayed in anysuitable location within the graphical user interface 600. For example,prompt 610 may be located along any border region of the graphical userinterface 600 (e.g., top, bottom, or side borders) (not shown), acrossan upper region (shown), or in any other suitable location. Further, asdescribed herein, prompt 610 may be partially transparent (not shown)such that ventilatory displays and data may be at least partiallyvisible behind prompt 610.

Specifically, prompt 610 may alert the clinician that increasedresistance has been detected, for example by notification message 612.As described herein, notification message 612 may alert the clinician ofan increase in resistance via any suitable means, e.g., “IncreasedResistance Detected.” Prompt 610 may further include informationregarding one or more potential causes for the increased resistance. Forexample, if the ventilator determined that the increased resistance waslikely caused by a clogged expiratory filter, this information may beprovided to the clinician (e.g., “Increased Resistance Detected,Expiratory Filter Likely Clogged”) (not shown). Prompt 610 may furtherinclude information regarding one or more recommendations for mitigatingthe increased resistance. With reference to the above example, if theventilator determined that the increased resistance was likely caused bya clogged expiratory filter, the ventilator may provide a recommendationto the clinician (e.g., “Increased Resistance Detected, Check ExpiratoryFilter”) (shown). According to the illustrated embodiment,recommendation message 614 is provided along with the notificationmessage 612 in a banner. According to alternative embodiments, thenotification message 612 alone may be provided on an initial prompt (notshown).

As may be appreciated, the disclosed data, graphics, and smart promptillustrated in graphical user interface 600 may be arranged in anysuitable order or configuration such that information and alerts may becommunicated to the clinician in an efficient and orderly manner. Thedisclosed data, graphics, and smart prompt are not to be understood asan exclusive array, as any number of similar suitable elements may bedisplayed for the clinician within the spirit of the present disclosure.Further, the disclosed data, graphics, and smart prompt are not to beunderstood as a necessary array, as any number of the disclosed elementsmay be appropriately replaced by other suitable elements withoutdeparting from the spirit of the present disclosure. The illustratedembodiment of the graphical user interface 600 is provided as an exampleonly, including potentially useful information and alerts that may beprovided to the clinician to facilitate communication of the detectedfluctuation in resistance in an orderly and informative way, asdescribed herein.

FIG. 7 is an illustration of an embodiment of a graphical user interfacedisplaying a prompt comprising an increased resistance notification andan expanded prompt comprising one or more recommendations for mitigatingthe increase in resistance during ventilation of a patient.

Graphical user interface 700 may display various monitored and/orderived data to the clinician during ventilation of a patient, asdescribed with reference to graphical user interface 600.

According to embodiments, the ventilator may monitor and evaluatevarious ventilatory parameters based on one or more predeterminedthresholds to detect a fluctuation in resistance. In some cases, theventilator may determine that the fluctuation in resistance is adecrease in resistance. In other cases, the ventilator may determinethat the fluctuation in resistance is an increase in resistance. Forexample, a detection of positive end-expiratory flow (EEF) may beindicative of an increase in resistance. However, according to someembodiments, when positive EEF is detected, the ventilator may make adetermination that resistance has increased by evaluating additionalventilatory data such as trended resistance, evaluation of PV loops,evaluation of ventilator setup data, etc. Upon a determination thatresistance has increased, the graphical user interface 700 may display aprompt, e.g., prompt 702.

According to embodiments, prompt 702 may be displayed in any suitablelocation such that a clinician may be alerted regarding the detectedincrease in resistance, but while allowing other ventilatory displaysand data to be visualized substantially simultaneously, as describedabove with reference to prompt 610.

Specifically, prompt 702 may alert the clinician that increasedresistance has been detected, for example by a notification message(e.g., “Increased Resistance Detected”).

According to embodiments, prompt 702 may be expanded to provideadditional information and/or recommendations to the clinician regardingthe detected fluctuation in resistance (e.g., increase in resistance).For example, an expand icon 704 may be provided within a suitable areaof the prompt 702. According to embodiments, upon selection of theexpand icon 704 via any suitable means, the clinician may optionallyexpand prompt 702 to acquire additional information and/orrecommendations for mitigating the detected increase in resistance, e.g.expanded prompt 706. As described above for prompt 610, expanded prompt706 may be displayed as a tab, icon, button, banner, bar, or any othersuitable shape or form. Further, expanded prompt 706 may be displayed inany suitable location within the graphical user interface 700. Forexample, expanded prompt 706 may be displayed below (shown) prompt 702,to a side (not shown) of prompt 702, or otherwise logically associatedwith prompt 702. According to other embodiments, an initial prompt maybe hidden (not shown) upon displaying expanded prompt 706. Expandedprompt 706 may also be partially transparent (not shown) such thatventilatory displays and data may be at least partially visible behindexpanded prompt 706.

According to embodiments, expanded prompt 706 may comprise additionalinformation (not shown) and/or one or more recommendation messages 708regarding a detected fluctuation in resistance (e.g., an increase inresistance). For example, the one or more recommendation messages 708may include one or more primary recommendation messages and one or moresecondary recommendation messages. According to embodiments, the one ormore primary recommendation messages may provide one or more suggestionsfor mitigating the increase in resistance based on more likely potentialcauses for the increase in resistance. The one or more secondaryrecommendation messages may provide one or more suggestions formitigating the increase in resistance based one less likely potentialcauses for the increase in resistance. For example, if an increase inresistance was likely caused by inflammation of the airways and thepatient was diagnosed with ARDS, a primary recommendation message mayinclude: “Consider Bronchodilator Therapy.” Additionally, according toembodiments, a secondary recommendation message may include: “ConsiderSuctioning Patient Airway.”

According to embodiments, expanded prompt 706 may also include one ormore hyperlinks 710, which may provide immediate access to the displayand/or settings screens associated with a detected fluctuation inresistance. For example, associated parameter settings screens may beaccessed from expanded prompt 706 via hyperlink 710 such that theclinician may address the detected fluctuation in resistance byadjusting one or more parameter settings as necessary. Alternatively,associated parameter display screens may be accessed such that theclinician may view clinical data associated with the detectedfluctuation in resistance in the form of charts, graphs, or otherwise.That is, according to embodiments, the clinician may access theventilatory data that implicated the detected fluctuation in resistancefor verification purposes.

As may be appreciated, the disclosed data, graphics, and smart promptillustrated in graphical user interface 700 may be arranged in anysuitable order or configuration such that information and alerts may becommunicated to the clinician in an efficient and orderly manner. Thedisclosed data, graphics, and smart prompt are not to be understood asan exclusive array, as any number of similar suitable elements may bedisplayed for the clinician within the spirit of the present disclosure.Further, the disclosed data, graphics, and smart prompt are not to beunderstood as a necessary array, as any number of the disclosed elementsmay be appropriately replaced by other suitable elements withoutdeparting from the spirit of the present disclosure. The illustratedembodiment of the graphical user interface 700 is provided as an exampleonly, including potentially useful information and alerts that may beprovided to the clinician to facilitate communication of the detectedfluctuation in resistance in an orderly and informative way, asdescribed here.

FIG. 8 is an illustration of an embodiment of a graphical user interfacedisplaying a prompt comprising an increased resistance notification anda potential cause notification and an expanded prompt comprising one ormore recommendations for mitigating the increased resistance duringventilation of a patient.

As described above with reference to FIG. 7, a graphical user interface800 may display various monitored and/or derived data to the clinicianduring ventilation of a patient. In addition, graphical user interface800 may display a prompt 802 including a notification message regardinga detected fluctuation in resistance, e.g., “Increased ResistanceDetected” (shown) or “Decreased Resistance Detected” (not shown).According to some embodiments, one or more potential causes for thefluctuation in resistance may be displayed on prompt 802, e.g., “MucousPlugging Likely” (shown), “Bronchospasm Likely” (not shown), “ExpiratoryFilter Likely Clogged” (not shown), etc. According to embodiments, onlya most likely potential cause may be displayed on prompt 802. Accordingto alternative embodiments, one or more potential causes for afluctuation in resistance may be determined by the ventilator, but maynot be displayed to the clinician.

According to embodiments, as described above, an expand icon 804 may beprovided within a suitable area of prompt 802. Upon selection of theexpand icon 804, the clinician may optionally expand prompt 802 toacquire additional information and/or recommendations for mitigating afluctuation in resistance. For example, expanded prompt 806 may beprovided upon selection of expand icon 804. As described above forprompts 610 and 706, expanded prompt 806 may be displayed in anysuitable shape or form in any suitable location within the graphicaluser interface 800.

According to embodiments, expanded prompt 806 may comprise additionalinformation (not shown) and/or one or more recommendation messages 808regarding a detected fluctuation in resistance (e.g., an increase inresistance). For example, the one or more recommendation messages 808may include one or more primary recommendation messages and one or moresecondary recommendation messages. According to embodiments, the one ormore primary recommendation messages may provide one or more suggestionsfor mitigating the increase in resistance based on more likely potentialcauses for the increase in resistance. For example, if the ventilatordetermined that mucous plugging is a likely cause for the increase inresistance, a primary recommendation message may provide: “ConsiderSuctioning Patient Airway” (shown). The one or more secondaryrecommendation messages may provide one or more suggestions formitigating the increase in resistance based on less likely potentialcauses for the increase in resistance. For example, if the ventilatordetermined that a clogged expiratory filter is a less likely cause forthe increase in resistance, a secondary recommendation message mayprovide: “Consider Changing Expiratory Filter” (shown).

As described above, according to embodiments, expanded prompt 806 mayalso include one or more hyperlinks 810, which may provide immediateaccess to the display and/or settings screens associated with thedetected fluctuation in resistance. For example, associated parametersettings screens may be accessed from expanded prompt 806 via hyperlink810 such that the clinician may address the detected fluctuation inresistance by adjusting one or more parameter settings as necessary.Alternatively, associated parameter display screens may be accessed suchthat the clinician may view clinical data associated with the detectedfluctuation in resistance in the form of charts, graphs, or otherwise.

As may be appreciated, the disclosed prompt and recommendation messagesillustrated in graphical user interface 800 may be arranged in anysuitable order or configuration such that information and alerts may becommunicated to the clinician in an efficient and orderly manner.Indeed, the illustrated embodiment of the graphical user interface 800is provided as an example only, including potentially useful informationand recommendations that may be provided to the clinician to facilitatecommunication of suggestions for mitigating the detected fluctuation inresistance in an orderly and informative way, as described herein.

It will be clear that the systems and methods described herein are welladapted to attain the ends and advantages mentioned as well as thoseinherent therein. Those skilled in the art will recognize that themethods and systems within this specification may be implemented in manymanners and as such is not to be limited by the foregoing exemplifiedembodiments and examples. In other words, functional elements beingperformed by a single or multiple components, in various combinations ofhardware and software, and individual functions can be distributed amongsoftware applications at either the client or server level. In thisregard, any number of the features of the different embodimentsdescribed herein may be combined into one single embodiment andalternative embodiments having fewer than or more than all of thefeatures herein described are possible.

While various embodiments have been described for purposes of thisdisclosure, various changes and modifications may be made which are wellwithin the scope of the present disclosure. Numerous other changes maybe made which will readily suggest themselves to those skilled in theart and which are encompassed in the spirit of the disclosure and asdefined in the appended claims.

What is claimed is:
 1. A ventilator-implemented method for issuing aprompt in response to detecting a fluctuation in resistance duringventilation of a patient, the method comprising: retrieving ventilatorydata; identifying a maximum threshold and a minimum threshold forresistance; trending resistance during ventilation of the patient;detecting a fluctuation in resistance when the trended resistancebreaches one of the maximum threshold and the minimum threshold; anddisplaying a notification regarding detection of the fluctuation inresistance.
 2. The method of claim 1, further comprising retrievingpatient data, wherein the patient data comprises at least one of: apatient diagnosis, a patient predicted body weight (PBW), and a patentgender.
 3. The method of claim 1, further comprising: determining one ormore potential causes for the fluctuation in resistance based at leastin part on the retrieved ventilatory data.
 4. The method of claim 2,further comprising: determining one or more potential causes for thefluctuation in resistance based at least in part on the retrievedpatient data.
 5. The method of claim 3, further comprising: determiningone or more recommendations for mitigating the fluctuation in resistancebased on the determined one or more potential causes and at least someventilatory data; and displaying the one or more recommendations.
 6. Themethod of claim 4, further comprising: determining one or morerecommendations for mitigating the fluctuation in resistance based onthe determined one or more potential causes and at least some patientdata; and displaying the one or more recommendations.
 7. The method ofclaim 5, wherein displaying further comprises: displaying an icon foraccessing the one or more recommendations, wherein upon activating theicon the one or more recommendations are displayed.
 8. The method ofclaim 5, further comprising: displaying the notification regardingdetection of the fluctuation in resistance on an expandable prompt; anddisplaying an icon for expanding the prompt to display one or more of:the one or more potential causes for the fluctuation in resistance andthe one or more recommendations for mitigating the fluctuation inresistance.
 9. A ventilatory system for issuing a prompt in response todetecting a fluctuation in resistance during ventilation of a patient,comprising: at least one processor; and at least one memory,communicatively coupled to the at least one processor and containinginstructions that, when executed by the at least one processor, performa method comprising: retrieving ventilatory data; identifying a maximumthreshold and a minimum threshold for resistance; trending resistanceduring ventilation of the patient; detecting a fluctuation in resistancewhen the trended resistance breaches one of the maximum threshold andthe minimum threshold; and displaying a notification regarding detectionof the fluctuation in resistance.
 10. The ventilatory system of claim 9,further comprising: determining one or more potential causes for thefluctuation in resistance based at least in part on the retrievedventilatory data.
 11. The ventilatory system of claim 10, furthercomprising: determining one or more recommendations for mitigating thefluctuation in resistance based on the determined one or more potentialcauses and at least some ventilatory data; and displaying the one ormore recommendations.
 12. The ventilatory system of claim 10, displayingfurther comprises: displaying an icon for accessing the one or morepotential causes, wherein upon activating the icon the one or morepotential causes are displayed.
 13. The ventilatory system of claim 11,wherein displaying further comprises: displaying an icon for accessingthe one or more recommendations, wherein upon activating the icon theone or more recommendations are displayed.
 14. A graphical userinterface for displaying one or more prompts in response to detecting afluctuation in resistance, the ventilator configured with a computerhaving a user interface including the graphical user interface, thegraphical user interface comprising: at least one window; and one ormore elements within the at least one window comprising at least oneprompt element for communicating information regarding detection of afluctuation in resistance, wherein the at least one prompt elementdisplays a notification regarding the fluctuation in resistance.
 15. Thegraphical user interface of claim 14, wherein the at least one promptelement displays one or more potential causes for the fluctuation inresistance.
 16. The graphical user interface of claim 14, wherein the atleast one prompt element displays one or more recommendations formitigating the fluctuation in resistance.
 17. The graphical userinterface of claim 14, wherein the at least one prompt element is anexpandable prompt element, the expandable prompt element furthercomprising: a selectable icon, wherein upon selection the expandableprompt element displays one or more potential causes for the fluctuationin resistance.
 18. The graphical user interface of claim 14, wherein theat least one prompt element is an expandable prompt element, theexpandable prompt element further comprising: a selectable icon, whereinupon selection the expandable prompt element displays one or morerecommendations for mitigating the fluctuation in resistance.
 19. Aventilator processing interface for displaying one or more prompts inresponse to detecting a fluctuation in resistance, comprising: means forretrieving at least some ventilatory data; means for determining thefluctuation in resistance; and means for displaying a prompt comprisinga notification of the fluctuation in resistance.
 20. The ventilatorprocessing interface of claim 19, wherein the prompt further comprisesone or more recommendations for mitigating the fluctuation inresistance.